从 .cer 文件中获取公钥字节数组 - C#

Question

I'm trying to get the public key byte[] from a certificate.

My colleague used the command : openssl x509 -inform der -in certificate.cer -text -noout , which dumped the key on the console and then he copied it into a binary file.

My task is to do this using c# .

I used the following lines.

var cert = X509Certificate.CreateFromCertFile(
        "C:\\Users\\dhermann\\Downloads\\FirmKeyTest\\FirmwareSubordinateSSLTo20190201PublicKey.cer");
        byte[] publicKey = cert.GetPublicKey();

My colleagues bin file has 136 bytes while mine gives me 140 bytes and on top of that, the initial 7 bytes of mine are not included in his byte array, the following 128 are exactly the same as his but the last 8 are different (3 of them not being included in his byte array.

What am I doing wrong and how can I get the exact same public key array as his?

Answer 1

So I ended up resolving this problem. My colleague was only using the modulus and adding an exponent. I was able to resolve it with the help of this website .